'use strict';
var rank_desc = function(collection){
  var compare = function (x, y) {//比较函数
    if (x < y) {
        return -1;
    } else if (x > y) {
        return 1;
    } else {
        return 0;
    }
}
var a = collection.sort(compare)
  return a;
};

module.exports = rank_desc;
